board: phytec: imx8mm: Add PHYTEC phyCORE-i.MX8MM support

Add support PHYTEC phyCORE-i.MX8MM SOM.

Supported features:
 - 2GB LPDDR4 RAM
 - 1x 1Gbit Ethernet
 - eMMC
 - external SD
 - debug UART3
 - watchdog
 - i2c eeprom

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
diff --git a/arch/arm/mach-imx/imx8m/Kconfig b/arch/arm/mach-imx/imx8m/Kconfig
index 7771fc8..8615dc3 100644
--- a/arch/arm/mach-imx/imx8m/Kconfig
+++ b/arch/arm/mach-imx/imx8m/Kconfig
@@ -72,6 +72,11 @@
 	select SUPPORT_SPL
 	select IMX8M_LPDDR4
 
+config TARGET_PHYCORE_IMX8MM
+	bool "PHYTEC PHYCORE i.MX8MM"
+	select IMX8MM
+        select SUPPORT_SPL
+	select IMX8M_LPDDR4
 endchoice
 
 source "board/freescale/imx8mq_evk/Kconfig"
@@ -82,5 +87,6 @@
 source "board/technexion/pico-imx8mq/Kconfig"
 source "board/toradex/verdin-imx8mm/Kconfig"
 source "board/beacon/imx8mm/Kconfig"
+source "board/phytec/phycore_imx8mm/Kconfig"
 
 endif